Efficient and Stable Deep‐Red Phosphorescent Organic Light‐Emitting Diodes Based on an Iridium Complex Containing a Benzoxazole‐substituted Ancillary Ligand

In the deep red : A biscyclometalated deep‐red phosphorescent dopant containing a new ancillary ligand, iridium(III) bis(1‐phenylisoquinolinato‐ N , C 2 ′) (2‐(benzo[ d ]oxazol‐2‐yl)phenol) (Ir(piq) 2 bop) has been designed and synthesized. By doping the new complex into Bebq 2 (Bebq 2 =bis(10‐hydroxybenzo[h] quinolinato)beryllium), a saturated red‐emitting PHOLED device was obtained. At a luminescence of 100 cd m −2 , the device shows efficiencies of 10.3 cd A −1 and 9.1 Lm W −1 with CIE coordinates of (0.67, 0.33).